Lead pencil



, LEISTENSCHNEIDER Aug. 4, 1936. I

LEAD PENCIL Filed Jan. 29 1934 jlnvencor' Augusf Leisiqerisch'neider yPatented Aug. 4, 1 9 36 UNITED STATES LEAD ritNcn. AugustLeistenschnelder, Dusseldorf, Germany Application January 29, 1934,Serial No. 708,801

' in Germany January 31, 1933 13 Claims.

The present invention relates to a mechanical or magazine lead pencil,and particularly to one of the type in which the lead is advanced byiongitudinal or axial movement of a cap or operating member accessibleat the exterior of the pencil. The invention is, in some respects, amodification of and an improvement upon the pencil constructiondisclosed in United States Patent No. 1,969,085, granted Aug. '7, 1934,for a joint invention of August Leistenschneider and Konrad Kressel.

An object of the invention isthe provision of a generally improved andmore satisfactory pencil of this type.

I Another object isthe' provision, in apencil of this kind, of improvedlead gripping or clamping means, and particularly of such means designedso that the lead may be gripped relatively close to the writing point orend thereof, and so that, 20 when the gripping means releasesthe lead,it will release it positively and completely, without binding ordragging on the lead.

To these and other ends the invention resides in certain improvementsand combinations of 25 parts, all as will be hereinafter more fullydescribed, the novel features being pointed out in the claims at the endof the specification.

In the accompanying drawing:

Fig. 1 shows a mechanical lead pencil accord- 30 gig to the invention inlongitudinal section.

.Fig. 2 shows a magazine for lead pencils according to the invention inlongitudinal section. Referring to the drawing, the lead is gripped nearthe tip of the pencil by a clamping sleeve indicated in general at ll,this sleeve being split longitudinally through part or, preferably, allof its length, to form a plurality of "gripping or clamping fingers. Theextreme lower or forward ends of the fingers have exterior surfaceswhich 40 are of generally conical shape, converging steeply or sharplytoward their lower ends, as indicated at i, which surfaces may bedescribed as 'being tapered downwardly, or as growing smaller in adownward or forward direction. Rearward- 4 ly or above the downwardlytapered portion, these 55 or ledge 2. From this step 2 to a point nearthe (Cl. 120.1'l)

rear ends of the clamping fingers, the exterior surfaces of the fingersmay be substantially cylindrical, as shown, and the rear ends of thefingers are loosely hung at the lower end of the lead tube 9, in amanner similar to or identical with the manner in which the fingers i9and 20 are hung in said Patent No. 1,969,085.

The inner surfaces of the fingers 0, near their forward ends, are ofarcuate cross section and of a radius substantially equal to that of thelead intended to be used in thit pencil. Near the middle of the lengthof the fingers, the inner surfaces of the fingers are conical, incliningor sloping obliquely outwardly and rearwardly, as

shown, and thence the inner surfaces continue .reardly with a crosssectional radius sufficiently large so as not to bear against the leadto any, substantial extent. Hence, when the clamping fingers are movedradially inwardly toward each other, by the clamping ring hereafterdescribed, the fingers will grip a stick of lead extending centrallythrough the fingers, and this gripping will take'place at and near thelower ends of the fingers but not at the upper ends of the fingers,where the diameter of the internal space through the fingers is greaterthan that of the lead. The fingers preferably grip the lead throughoutan axial extent or length of at least 1.5 times the diameter of thelead.

The clamping ring, for operating the fingers of the clamping sleeve 0 togrip or release the lead, is indicated in general at 4. Intermediate itslength, the ring has a shoulder 8, and a substantially cylindricaltubular portion of larger diameter extends rearwardly from thisshoulder, terting in an outwardly extending annular flange 6. A coiledspring I, surrounding this part of the clamping ring, pressesrearwardlyon the flange 6 and constantly tends to move the clamping ringrearwa-rdly until the upper or rearward surface 8' of the fiange 6 comesinto contact with the front surface I of a block or member I secured infixed position in thepencil casing, and preferably split longitudinallyinto two parts, for ease of assembly. From the shoulder 8, anothertubular portion of the clamping ring, of smaller cross-sectionaldiameter than the first mentioned portion, extends forwardly to aforward end or edge 3. This last mentioned tubular portion at itsforward end has its inner surface conicaliy shaped to be substantially.complemental to and cooperate with the conical outer surfaces of thefingers immediately forwardly of the shoulder 2, as will be readily seenfrom the drawing. If the clamping ring be moved forwardly relatively. to

the clamping fingers, the ring will force the fingers radially inwardlytoward each other to grip an interposed lead. If the ring be movedrearwardly relatively to the fingers, the fingers will be released fromthe lead, gradually at first,

nose piece or casing ll, preferably of resilientmetal and longitudinallysplit at its forward end. It will be noted from the drawing that thecavity or chamber within this nose piece H is of sumcient diameter toaccommodate the lead clamping parts, almost to the extreme end of thepencil,

clamping ring when the thus enabling the clamping parts to be broughtvery close to the writing end of the lead. Yet,

with the design here shown, this does not make the exterior of the nosepiece of awkward size or shape. The exterior of the nose piece may be ofdecreasing size in aforward direction, as shown, and may be described astapered forwardly. A shoulder l within the nose piece contacts with theshoulder 8 of the clamping ring to limit forward movement of the ring.

To reduce the cost of production, it is desirable to make the clampingfingers and clamping ring of a soft, easily workable metal, such, forexample, as brass, aluminum, duraiuminum, German silver, copper, oralloys of such metals. According to the present invention, those partsof the soft metal which are exposed to strong friction, such as theparts marked '41 and 48 in Fig. 1, have applied to them coating orcovering layers 49 and 50 of a hard wear-resisting metal, whichpreferably is also resistant to'acids and non-rusting. Suitable metalsfor this purpose are nickel, chromium, tungsten, iridium, platinum,palladium, molybdenum, and the like. These wear-resisting coatings orlinings greatly increase the life of the clamping parts, without undulyincreasing the cost of construction.

As above stated, the loosely connected to or clamping fingers I are hungfrom the forward end of the lead tube 9. This leadtube has a shoulder l1cooperating with the surface ii of the stationary member 1, to limitrearward movement of the tube so that the clamping fingers cannot bedrawn too far rearwardly through the ring is already at the rearwardlimit of its motion, particularly when there is no lead in the tube,thus avoiding Jamming and injury of the parts. The tube also has ashoulder l9 cooperating with a surface It on the stationary member 1, tolimit forward movement of the tube and prevent the feeding fingers frombeing jammed against the front wall of the nose piece II. To the extentpermitted by these shoulders 11 and it, the lead tube 9 may movelongitudinally within the pencil casing, and is constantly urgedrearwardlyby a coiled spring 9' which presses at its forward end againstthe stationary member 1 and at its rear end against the lead tube orsome part connected thereto, such as the member 21.

In the preferred form of construction, the member 21 is dividedlongitudinally into two pieces, for ease-of assembly, and constitutesthe bottom of a lead me or reservoir. The side walls 22 of the magazineare fixed, as by means of an annular groove 29, tothe bottom member 21.The magazine is slidable axially or longitudinally within the main metalcasing member or tube 2|, which may be surrounded by an exterior sheathor sleeve 20 of any suitable material, such as an artificial mass. Theupper end of the magazine walls 22 may be provided with a screw thread23, for engaging a'threaded armular member 24 the upper end of which isclosed by a plug 25 having an annular flange 26 which may beconveniently grasped for unscrewing the members 24 and 25 from themagazine walls 22. when the closure is thus unscrewed, the interiorspace SI of the lead magazine may be filled with leads, which will reston the conical surface 29 of the bottom member 21, and one at a time theleads will fall into and fill the space 3! within the lead tube 9. vFrequently it is desirable not to fix the magazine bottom 21 rigidly tothe lead tube 9, but to provide for some relative movement between theseparts at each feeding operation, so as to disturb the leads within themagazine and prevent them from jamming therein. To this end,-

annular flanges 32. and 33 may be formed on the! tube 9, the flange 32being located within an annular recess in the member 21, which recesshas a rear end 34 and a forward end 35. The forward limit of movement ofthe tube 9 relative to the magazine member 21 is defined by contact ofthe flange 32 with the surface 35, while the rearward limit of relativemovement is defined by contact of the flange 33 with the front end ofthe member 21 and simultaneous contact of the flange 32 with the surface34, thus giv-' ing a good bearing on two parts so that too 35' heavy astress on a small area of the tube 9 during a forward feeding operationis avoided. when. the tube it moves rearwardiy relatively to themagazine bottom 21, upon pushing down' on the cap 26, a projection 36 onone side of therear end of the tube 9, shaped. somewhat likethe point ofa shovel, enters the lead space 30 in the magazine and disturbs theleads therein, pushing aside any leads blocking the filling opening andfacilitating the sliding of a single lead into the filling tube 9.

The form of the lead pencil described may be altered in different wayswithin the scope of the present invention.

Working of the the clamping-sleeve II and the clamping-ringwheld firmlythereto by adhesion and holding the said clamping-sleeve together, ispressed forward until the shoulder 8 rests upon the pro-' jection HI. v

'Further forward movement of the tube ,gg' caused by further pushingupon the cap 28, causes the clamping sleeve 0 to slide forwardly throughthe clamping ring 4, since the ring can not move any farther forwardly.The frictional adhesion between the sleeve and the ring is thus r d-#ually lessened, until it is overcome by the force of the spring 5, whichthen returns the clamping ring to its rearmost positio thus completelyreleasing the clamping fingers from the.

lead and permitting the fin ers to spread far casing.

apart so that they will not bind or drag on the lead when they moverearwardly. The cap 26 is then released, and the spring 9' -moves thecap, the tube 9, and the clamping sleeve 0 rearwardlyywithout changingthe position of the lead. .Duri'ngthis movement, the fingersof theclamping sleeve are drawn rearwardly through the clamping ring, whichcannot move any farther rearwardly, and near'the end of this rearwardmovement the relative motion between the fingers and the ring causes thefingers to clamp upon the lead, holdingit' firmly for writing untilfurther advancement of the lead'is needed. Then, when feeding isdesired, forward movement of the cap 26 moves the tube 9 and theclamping fingers 0 forwardly, the clamping ring 4 adhering frictionallyto the fingers and moving forwardly with them against the force of thespring 5, so that the fingers remain tightly clamped on the lead andadvance the lead, until the fingers are released near the forward end ofthe movement, as above explained.

It is now seen that an improved pencil has been provided, in which thelead is effectively gripped and completely released at the proper time.With this improved design and construction, the lead is gripped muchcloser to the nose of the pencil than in the prior construction i1-lustrated in said Patent No. 1,969,085, with the result that less leadis wasted at the end of each piece or stick, and the lead is held moresatisfactorily. Also, .in this improved construction the lead isreleased more completely and satisfactorily than in the priorconstruction, so that all danger of accidental rearward movement of thelead is avoided.

Another advantage of the present improved construction is that the nosepiece II may be readilyv removed for cleaning the clamping fingers, whenrequired, without causing any of the other parts to become loose or fallout. It is seen from Fig. 1 that the nose piece is screwed onto theforward end of the main casing parts. When it is unscrewed and removedtherefrom, the clamping fingers are readily accessible for cleaning,especially if they be pushed forwardly by pressure on thecap 26. Inspite of the removal of the shoulder ill of the nose piece out of thepath of the shoulder 8 on the clamping ring, the clamping ring still cannot drop out, ash; is held in place by its fiange or shoulder 8, whichcan not; pass through the front ofthe Certain features disclosed but notclaimed herein, and particularly the construction of the lead-magazine,are claimed in my companion application for Magazine for leadpencil,Serial No. 708,802, filed January 29, 1934.

I claim:

1. A mechanical pencil comprising a casing havinga nose of externalcross sectional dimensions decreasingtoward its forward end, said havinga nose whose external sides converge tomay lie within said portion ofsaid cavity-closely adjacent saidjforward end of said nose, and

means for-closing said fingers upona lead near the rear end of areciprocation of said fingers and releasingsaid fingers fromsaid leadnear the forward end or a reciprocation.

2. A mechanical pencil comprising a casing having a nose at leastpartially tapered toward its forward end, said nose having therein acavity having a portion alsotapered with thesmaller 9 end of saidportionof said cavity closely adjacent said forward end of said nose, lead'grasping means mounted for forward and backward reciprocation withinsaid casing, said grasping means including a plurality of fingersmovable laterally toward and'away from a lead and having terminalportions taperedtoward their forward its forward end, said nose havingtherein a cavity having a portion shaped to contract toward said forwardend with the smaller end of said portion of said cavity closelyadjacentsaid forward end of said nose, lead grasping means 35 portions may liewithin said converging portion of said cavity closely adjacent saidforward end of said nose, said fingers also having, rearwardly of saidterminal portions, other portions with outer sides diverging graduallytoward said forward ends andrelieved suddenly at their rear ends, and aclamping ring surrounding said fingers and adapted to cooperate withsaid diverg.-' ing portion to clamp said fingers upon a'lead and to moveofi of said diverging portions past the relieved ends thereof to unclampsaid fingers and free them for substantial movement away from. a lead.

4. A mechanical pencil comprising a casing, a tube mounted forreciprocation within said casing, a plurality of lead-engaging fingersoperatively connected to said tube and extending for wardly therefrom,and a clamping member also 60 movable within said casing, said clampingmember including a tubular portion of one size cooperating withsaid'fingers to cause them to clamp a lead and a tubular portion of adifferent size extending rearwardly and at least partially 65 encirclingsaid tube near its forward end.

5. A mechanical pencil comprising a casing, a tube mounted forreciprocation within said casing. a plurality of lead-engaging fingersoperatively connected to said tube and extending forwardly therefrom, aclamping member also movable within said casing, said clamping memberincluding adjacent its forward end a tubular portion of smaller size atleast partially encircling said fingers and cooperating with them tocause 7 operatively connected thereto to tend to move said clampingmember in a rearward direction.

7. A mechanical pencil comprising a casing, a plurality of lead-engagingfingers mounted for forward and backward movement within said casing,said fingers having portions tapered externally in a rearward direction,abutment means within said-casing, and a finger clamping member movablymounted in said casing, said member' including a portion of smallertransverse dimension extending forwardly for cooperation with saidfingers to cause them to clamp a lead, and

a portion of larger transverse dimension extending rearwardly forcooperation with said abutment means to limit rearward movement of saidmember. v

8.'A mechanical pencil comprising a casing, a plurality of lead-engagingfingers -mounted for forward and backward movement within said casing,said fingers having portions with exterior surfaces diverging in aforward direction, and a member surrounding said fingers and shapedinternally to cooperate with said diverging portionsof said fingers andcapable of relative longitudinal movement with respect to said fingers,so that whensaid member is moved forwardly with respect to saiddiverging portions of said fingers, said fingers will be contracted toclamp upon a lead, and when said member is moved rearwardly with respectto said diverging portions of said fingers, said fingers may expand tofree a lead, said fingers being suddenly relieved at the rear ends ofsaid diverging portions so that when said member is moved beyond saidrear ends of said diverging portions said fingers may expand to amaterially greater ,extent.

9. A mechanical pencil comprising a casing,- -a plurality oflead-engaging fingers mountedv for forward and backward movement withinsaid casing, said fingers throughout portions of their lengths havingexterior surfaces diverging in a forward direction and thence convergingsubstantially from said diverging portions to their forward ends, sothat said forward ends may lie closely adjacent the forward end of thepencil, and, a member. surrounding said fingers and shaped internally tocooperate with said diverging portions thereof, to cause a clampingaction of said fingers upon a lead and to allow release thereof:

ii). A mechanical pencil comprising a casing,

a tube mounted for reciprocation within said casing, .a plurality oflead-engaging fingers operat-lvely connected to said tube and extendingforwardly therefrom, a clamping member also movable within said casingfor cooperation with gers are reciprocated vanced position normallylying at least partially within said removable nose portion so that saidfingers may be rendered accessible for inspection and cleaning byremoval of said nose portion, a clamping ring also mounted within saidcasing for movement back and forth with relation to said fingers tocause said fingers to grasp and release a lead, and means other thansaid fingers themselves for preventing removal of said clamping ringfrom said casing in a forward direction notwithstanding removal of saidnose portion. a

12. A mechanical pencil comprising a' main casing, a lead holding tubemounted for reciprocation within said casing, a plurality of leadclamping fingers loosely mounted on said tube and projecting forwardlytherefrom beyond the forward end of said main casing, a clamping ringhaving a portion within said main casing and a portion projectingforwardly therefrom and surrounding the forwardly projecting portions ofsaid fingers, and a nose piece detachably secured to said main casingand extending forwardly from the forward end thereof and enclosing theforwardly projecting portions of said fingers and clamping ring.

13. A mechanical pencil comprising a casing having a nose tapered;toward its forward end, said nose having therein a cavity havingaportion tapered toward said forward end with the smaller end of saidtapered portion of said cavity closely adjacent said forward end of saidnose, lead grasping means mounted for forward and backward reciprocationwithin said casing, said grasping means including a plurality of fingersmovable laterally toward and away from a lead andhaving terminalportions tapered toward their forward ends so that when saidfinforwardly said terminal portions may lie within said taperedportion'of said cavity closely adjacent said forward end of said-nose,said fingers also having, rearwardiy of said terminal portions, otherportions conically tapered-toward their rearward ends; and relievedsuddenly at their rear ends, and a clamping ring surrounding saidfingers and having a conically shaped inner surface adapted to oooperatewith said conically tapered portions of 00 beyond their relieved rearends to unclamp said fingers and free them for substantial movement awayfrom a lead. 1

AUGUST ms'rnuscnmsmsa.

